MONITORING AND EVALUATION OF ERECTILE FUNCTION DURING ROBOT-ASSISTED RADICAL PROSTATECTOMY
Keywords:
robot-assisted radical prostatectomy, neurovascular bundles, electrical nerve stimulation, physiological measurements
Abstract
To optimize the removal of cancerous prostate tissue, nerve-sparing robot-assisted radical prostatectomy (RARP) is commonly used. This technique aims to preserve the neurovascular bundles (NVBs), damage to which is a major cause of postoperative erectile dysfunction (ED). The primary goal of this study was to develop and assess a novel intraoperative NVB stimulation (NVBS) system designed to elicit penile erectile responses during RARP and assist in predicting postoperative erectile function (EF). The stimulation paradigm involved applying trains of rectangular and quasi-trapezoidal stimulating pulses (stimuli) to the apical, mid, and basal portions of the NVBs for approximately 60 s, both before and after the nerve-sparing dissection. The stimulation probe was developed with a consideration of nerve-stimulation models, NVB anatomy, and surgical constraints. Electrodes made of platinum were embedded in denture-grade material and mounted in a titanium housing. To evaluate the erectile responses, a multi-sensor probe was designed to monitor axial penile rigidity (ARIG), galvanic skin response (GSR), and glans temperature Tgp. Additionally, corpus cavernosum electromyography (CC-EMG) was recorded using surface and needle electrodes. Among five male patients enrolled, two showed noticeable CC-EMG activity, but none demonstrated a measurable increase in axial penile rigidity. The CC-EMG data were limited to short-term monitoring and could not be reliably analyzed in the time or frequency domains. In conclusion, although the stimulation protocol did not trigger measurable erectile responses, CC-EMG signals offered intraoperative insights into NVB integrity. This information may support more accurate predictions of erectile function recovery following RARP.
References
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12. B. Alsaid, T. Bessede, D. Diallo, D. Moszkowicz, I. Karam, G. Benoît & S. Droupy, Division of autonomic nerves within the neurovascular bundles distally into corpora cavernosa and corpus spongiosum components: immunohistochemical confirmation with three-dimensional reconstruction, Eur. Urol., 59(2011)6, 902–909, doi:10.1016/j.eururo.2011.02.031
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15. H. W. Axelson, E. Johansson & A. Bill-Axelson, Intraoperative Cavernous Nerve Stimulation and Laser-Doppler Flowmetry during Radical Prostatectomy, J. Sex. Med., 10(2013)11, 2842–2848, doi:10.1111/j.1743-6109.2012.02892.x
16. G. Y. Tan, S. Grover, A. Takenaka, P. Sooriakumaran, A. K. Tewari, Current Concepts in Cavernosal Neural Anatomy and Imaging and Their Implications for Nerve-Sparing Radical Prostatectomy in Robotics in Genitourinary Surgery, Springer, London 2011, 273-289, doi: 10.1007/978-1-84882-114-9_24
17. S. Unal, B. Musicki & A. L. Burnett, Cavernous nerve mapping methods for radical prostatectomy, Sex. Med. Rev., 11(2023)4, 421-430, doi:10.1093/sxmrev/qead030
18. Z.-P. Fang, J. T. Mortimer, Selective activation of small motor axons by quasitrapezoidal current pulses, IEEE Trans. Biomed. Eng., 38(1991)2, 168-174, doi:10.1109/10.76383
19. E. M. Hudak, J. T. Mortimer & H. B. Martin, Platinum for neural stimulation: voltammetry considerations, J. Neural Eng., 7(2010)2, 26005, doi:10.1088/1741-2560/7/2/026005
20. T. J. A. G. Münker, S. E. C. M. van de Vijfeijken, C. S. Mulder, V. Vespasiano, A. G. Becking, C. J. Kleverlaan, A. G. Becking, L. Dubois, L. H. E. Karssemakers, D. M. J. Milstein, S. E. C. M. van de Vijfeijken, P. R. A. M. Depauw, F. W. A. Hoefnagels, W. P. Vandertop, C. J. Kleverlaan, T. J. A. G. Münker, T. J. J. Maal, E. Nout, M. Riool & S. A. J. Zaat, Effects of sterilization on the mechanical properties of poly(methyl methacrylate) based personalized medical devices, J. Mech. Behav. Biomed. Mater., 81(2018), 168-172, doi:10.1016/j.jmbbm.2018.01.033
21. S. Asadian, A. Khatony, G. R. Moradi, A. Abdi, & M. Rezaei, Accuracy and precision of four common peripheral temperature measurement methods in intensive care patients, Med. Devices (Auckl.), 9(2016), 301–308, doi:10.2147/MDER.S109904
22. V. F. S. Tsai, H.-C. Chang, S.-P. Liu, Y.-C. Kuo, J.-H. Chen, F.-S. Jaw & J.-T. Hsieh, Determination of Human Penile Electrical Resistance and Implication on Safety for Electrosurgery of Penis, J. Sex. Med., 7(2010)8, 2891-2898, doi:10.1111/j.1743-6109.2010.01856.x
23. A. Sanchez-Comas, K. Synnes, D. Molina-Estren, A. Troncoso-Palacio & Z. Comas-González, Correlation Analysis of Different Measurement Places of Galvanic Skin Response in Test Groups Facing Pleasant and Unpleasant Stimulating pulses, Sensors (Basel), 21(2021)12, 4210, doi:10.3390/s21124210
24. S. E. Hyun, K. Kim, Intra-operative cavernous nerve monitoring and mapping during radical prostatectomy: a case report of corpus cavernosum electromyography, J. Intraoper. Neurophysiol., 3(2021)2, 97-101, doi:10.33523/join.2021.3.2.97
25. G. U. Roh, Y. Song, J. Park, Y. M. Ki & D. W. Han, Effects of propofol on the inflammatory response during robot-assisted laparoscopic radical prostatectomy: a prospective randomized controlled study, Sci. Rep., 9(2019), 5242, doi:10.1038/s41598-019-41708-x
26. A. Takenaka, A. Tewari, R. Hara, R. A. Leung, K. Kurokawa, G. Murakami & M. Fujisawa, Pelvic autonomic nerve mapping around the prostate by intraoperative electrical stimulation with simultaneous measurement of intracavernous and intraurethral pressure, J. Urol., 177(2007)1, 225-229, doi:10.1016/j.juro.2006.08.104
27. P. Pečlin & J. Rozman, Alternative paradigm of selective vagus nerve stimulation tested on an isolated porcine vagus nerve, The Scientific World Journal 2014(2014), 310283, doi:10.1155/2014/310283
28. A. L. Burnett & T. F. Lue, Neuromodulatory therapy to improve erectile function recovery outcomes after pelvic surgery, J. Urol., 176(2006)3, 882-7, doi:10.1016/j.juro.2006.04.020
29. W. H. Song, J. H. Park, B. S. Tae, S.-M. Kim, M. Hur, J.-H. Seo, J. H. Ku, C. Kwak, H. H. Kim, K. Kim & C. W. Jeong, Establishment of novel intraoperative monitoring and mapping method for the cavernous nerve during robot-assisted radical prostatectomy: results of the phase I/II, first-in-human, feasibility study, Eur. Urol., 78(2020)2, 221-228, doi:10.1016/j.eururo.2019.04.042
30. R. Tal, P. Teloken & J. P. Mulhall, Erectile function rehabilitation after radical prostatectomy: Practice patterns among AUA members, J. Sex. Med., 8(2011)8, 2370-2376, doi:10.1111/j.1743-6109.2011.02355.x
31. I. Kyriazis, T. Spinos, A. Tsaturyan, P. Kallidonis, J. U. Stolzenburg & E. Liatsikos, Different Nerve-Sparing Techniques during Radical Prostatectomy and Their Impact on Functional Outcomes. Cancers (Basel) 14(2022)7, 1601, doi: 10.3390/cancers14071601, doi:10.3390/cancers14071601
32. I. Goldstein, D. G. Udelson, Axial penile rigidity: determinants and relation to hemodynamic parameters, Int. J. Impot. Res., 10(1998)Suppl 2, S28-33, discussion S49-51
33. G. Wagner, X. Jiang, Corpus cavernosum electromyography, a usable clinical diagnostic method for erectile dysfunction? Indian Journal of Urology, 22(2006)3, 225-230, doi:10.4103/0970-1591.27629
2. P. C. Walsh, H. Lepor & J. C. Eggleston, Radical prostatectomy with preservation of sexual function: Anatomical and pathological considerations, The Prostate, 4(1983)5, 473-485, doi:10.1002/pros.2990040506
3. H. Lepor, M. Gregerman, R. Crosby, F. K. Mostofi & P. C. Walsh, Precise localization of the autonomic nerves from the pelvic plexus to the corpora cavernosa: a detailed anatomical study of the adult male pelvis, J. Urol., 133(1985)2, 207-212, doi:10.1016/s0022-5347(17)48885-9
4. P. N. Schlegel, P. C. Walsh, Neuroanatomical approach to radical cystoprostatectomy with preservation of sexual function, J. Urol., 138(1987)6, 1402-1406, doi:10.1016/s0022-5347(17)43655-x
5. P. C. Walsh, J. I. Epstein & F. C. Lowe, Potency following radical prostatectomy with wide unilateral excision of the neurovascular bundle J. Urol., 138(1987)4, 823-827, doi:10.1016/s0022-5347(17)43385-4
6. J. Rehman, G. J. Christ, A. Kaynan, D. Samadi & J. Fleischmann, Intraoperative electrical stimulation of cavernosal nerves with monitoring of intracorporeal pressure in patients undergoing nerve sparing radical prostatectomy, BJU Int., 84(1999)3, 305–310, doi:10.1046/j.1464-410x.1999.00143.x
7. A. J. Costello, M. Brooks & O. J. Cole, Anatomical studies of the neurovascular bundle and cavernosal nerves, BJU Int. 94(2004)7, 1071–1076, doi:10.1111/j.1464-410X.2004.05106.x
8. S. Yucel, T. Erdogru, M. Baykara, Recent neuroanatomical studies on the neurovascular bundle of the prostate and cavernosal nerves: clinical reflections on radical prostatectomy, Asian Journal of Andrology, 7(2005)4, 339-349, doi:10.1111/j.1745-7262.2005.00097.x
9. S. Hisasue, K. Hashimoto, K. Kobayashi, M. Takeuchi, Y. Kyoda, S. Sato, N. Masumori & T. Tsukamoto, Baseline erectile function alters the cavernous nerve quantity and distribution around the prostate, J. Urol., 184(2010)5, 2062–2067, doi:10.1016/j.juro.2010.06.108
10. J. Walz, A. L. Burnett, A. J. Costello, J. A. Eastham, M. Graefen, B. Guillonneau, M. Menon, F. Montorsi, R. P. Myers, B. Rocco & A. Villers, A critical analysis of the current knowledge of surgical anatomy related to optimization of cancer control and preservation of continence and erection in candidates for radical prostatectomy, Eur. Urol., 57(2010)2, 179–92, doi:10.1016/j.eururo.2009.11.009
11. B. Alsaid, I. Karam, T. Bessede, I. Abdlsamad, J.-F. Uhl, V. Delmas, G. Benoît & S. Droupy, Tridimensional Computer-Assisted Anatomic Dissection of Posterolateral Prostatic Neurovascular Bundles, Eur. Urol., 58(2010)2, 281-287, doi:10.1016/j.eururo.2010.04.002
12. B. Alsaid, T. Bessede, D. Diallo, D. Moszkowicz, I. Karam, G. Benoît & S. Droupy, Division of autonomic nerves within the neurovascular bundles distally into corpora cavernosa and corpus spongiosum components: immunohistochemical confirmation with three-dimensional reconstruction, Eur. Urol., 59(2011)6, 902–909, doi:10.1016/j.eururo.2011.02.031
13. G. M. Villeirs, K. L.Verstraete, W. J. De Neve & G. O. De Meerleer, Magnetic Resonance Imaging Anatomy of the Prostate and Periprostatic Area: A Guide for Radiotherapists, Radiother. Oncol., 76(2005)1, 99-106, doi:10.1016/j.radonc.2005.06.015
14. E. E. Clarebrough, B. J. Challacombe, C. Briggs, B. Namdarian, R. Weston, D. G. Murphy & A. J. Costello, Cadaveric Analysis of Periprostatic Nerve Distribution: An Anatomical Basis for High Anterior Release During Radical Prostatectomy? J. Urol., 185(2011)4, 1519-1525, doi:10.1016/j.juro.2010.11.046
15. H. W. Axelson, E. Johansson & A. Bill-Axelson, Intraoperative Cavernous Nerve Stimulation and Laser-Doppler Flowmetry during Radical Prostatectomy, J. Sex. Med., 10(2013)11, 2842–2848, doi:10.1111/j.1743-6109.2012.02892.x
16. G. Y. Tan, S. Grover, A. Takenaka, P. Sooriakumaran, A. K. Tewari, Current Concepts in Cavernosal Neural Anatomy and Imaging and Their Implications for Nerve-Sparing Radical Prostatectomy in Robotics in Genitourinary Surgery, Springer, London 2011, 273-289, doi: 10.1007/978-1-84882-114-9_24
17. S. Unal, B. Musicki & A. L. Burnett, Cavernous nerve mapping methods for radical prostatectomy, Sex. Med. Rev., 11(2023)4, 421-430, doi:10.1093/sxmrev/qead030
18. Z.-P. Fang, J. T. Mortimer, Selective activation of small motor axons by quasitrapezoidal current pulses, IEEE Trans. Biomed. Eng., 38(1991)2, 168-174, doi:10.1109/10.76383
19. E. M. Hudak, J. T. Mortimer & H. B. Martin, Platinum for neural stimulation: voltammetry considerations, J. Neural Eng., 7(2010)2, 26005, doi:10.1088/1741-2560/7/2/026005
20. T. J. A. G. Münker, S. E. C. M. van de Vijfeijken, C. S. Mulder, V. Vespasiano, A. G. Becking, C. J. Kleverlaan, A. G. Becking, L. Dubois, L. H. E. Karssemakers, D. M. J. Milstein, S. E. C. M. van de Vijfeijken, P. R. A. M. Depauw, F. W. A. Hoefnagels, W. P. Vandertop, C. J. Kleverlaan, T. J. A. G. Münker, T. J. J. Maal, E. Nout, M. Riool & S. A. J. Zaat, Effects of sterilization on the mechanical properties of poly(methyl methacrylate) based personalized medical devices, J. Mech. Behav. Biomed. Mater., 81(2018), 168-172, doi:10.1016/j.jmbbm.2018.01.033
21. S. Asadian, A. Khatony, G. R. Moradi, A. Abdi, & M. Rezaei, Accuracy and precision of four common peripheral temperature measurement methods in intensive care patients, Med. Devices (Auckl.), 9(2016), 301–308, doi:10.2147/MDER.S109904
22. V. F. S. Tsai, H.-C. Chang, S.-P. Liu, Y.-C. Kuo, J.-H. Chen, F.-S. Jaw & J.-T. Hsieh, Determination of Human Penile Electrical Resistance and Implication on Safety for Electrosurgery of Penis, J. Sex. Med., 7(2010)8, 2891-2898, doi:10.1111/j.1743-6109.2010.01856.x
23. A. Sanchez-Comas, K. Synnes, D. Molina-Estren, A. Troncoso-Palacio & Z. Comas-González, Correlation Analysis of Different Measurement Places of Galvanic Skin Response in Test Groups Facing Pleasant and Unpleasant Stimulating pulses, Sensors (Basel), 21(2021)12, 4210, doi:10.3390/s21124210
24. S. E. Hyun, K. Kim, Intra-operative cavernous nerve monitoring and mapping during radical prostatectomy: a case report of corpus cavernosum electromyography, J. Intraoper. Neurophysiol., 3(2021)2, 97-101, doi:10.33523/join.2021.3.2.97
25. G. U. Roh, Y. Song, J. Park, Y. M. Ki & D. W. Han, Effects of propofol on the inflammatory response during robot-assisted laparoscopic radical prostatectomy: a prospective randomized controlled study, Sci. Rep., 9(2019), 5242, doi:10.1038/s41598-019-41708-x
26. A. Takenaka, A. Tewari, R. Hara, R. A. Leung, K. Kurokawa, G. Murakami & M. Fujisawa, Pelvic autonomic nerve mapping around the prostate by intraoperative electrical stimulation with simultaneous measurement of intracavernous and intraurethral pressure, J. Urol., 177(2007)1, 225-229, doi:10.1016/j.juro.2006.08.104
27. P. Pečlin & J. Rozman, Alternative paradigm of selective vagus nerve stimulation tested on an isolated porcine vagus nerve, The Scientific World Journal 2014(2014), 310283, doi:10.1155/2014/310283
28. A. L. Burnett & T. F. Lue, Neuromodulatory therapy to improve erectile function recovery outcomes after pelvic surgery, J. Urol., 176(2006)3, 882-7, doi:10.1016/j.juro.2006.04.020
29. W. H. Song, J. H. Park, B. S. Tae, S.-M. Kim, M. Hur, J.-H. Seo, J. H. Ku, C. Kwak, H. H. Kim, K. Kim & C. W. Jeong, Establishment of novel intraoperative monitoring and mapping method for the cavernous nerve during robot-assisted radical prostatectomy: results of the phase I/II, first-in-human, feasibility study, Eur. Urol., 78(2020)2, 221-228, doi:10.1016/j.eururo.2019.04.042
30. R. Tal, P. Teloken & J. P. Mulhall, Erectile function rehabilitation after radical prostatectomy: Practice patterns among AUA members, J. Sex. Med., 8(2011)8, 2370-2376, doi:10.1111/j.1743-6109.2011.02355.x
31. I. Kyriazis, T. Spinos, A. Tsaturyan, P. Kallidonis, J. U. Stolzenburg & E. Liatsikos, Different Nerve-Sparing Techniques during Radical Prostatectomy and Their Impact on Functional Outcomes. Cancers (Basel) 14(2022)7, 1601, doi: 10.3390/cancers14071601, doi:10.3390/cancers14071601
32. I. Goldstein, D. G. Udelson, Axial penile rigidity: determinants and relation to hemodynamic parameters, Int. J. Impot. Res., 10(1998)Suppl 2, S28-33, discussion S49-51
33. G. Wagner, X. Jiang, Corpus cavernosum electromyography, a usable clinical diagnostic method for erectile dysfunction? Indian Journal of Urology, 22(2006)3, 225-230, doi:10.4103/0970-1591.27629
Published
2026-02-02
How to Cite
1.
Rozman J, Bizjak J, Godec M, Ribarič S, Hawlina S. MONITORING AND EVALUATION OF ERECTILE FUNCTION DURING ROBOT-ASSISTED RADICAL PROSTATECTOMY. MatTech [Internet]. 2026Feb.2 [cited 2026Jul.14];60(1):3–11. Available from: https://mater-tehnol.si/index.php/MatTech/article/view/1461
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